Robotic surgery does not affect upstaging of T1 renal masses

Partial nephrectomy is the mainstay of treatment for localized kidney cancer. A proportion of patients are upstaged post-operatively to locally advanced disease (pT3a). We aimed to identify the incidence of upstaging to pT3a during partial nephrectomy and its relationship to a robotic approach. The National Cancer Database was queried for patients diagnosed with cT1M0 disease between 2010 and 2015 who underwent an open or robotic partial nephrectomy with final stage pT1-3a. Our primary outcome was rate of upstaging to pT3a in patients undergoing partial nephrectomy and secondary outcomes were stage migration, rate of positive margins, and overall survival (OS). The relationship between open and robotic surgery was examined. Logistical regression and Kaplan-Meier analyses were performed. Of 68,976 patients identified, 5.9% of patients were upstaged from cT1 to pT3a post-operatively. The incidence of upstaging to pT3a disease has increased from 5.7% in 2010 to 6.9% in 2015. Similarly, the proportion of patients undergoing a robotic approach is also increasing (31.6-64.4%); however, a robotic approach is not associated with pT3a upstaging on multivariable analysis. The probability of being upstaged was significantly proportional to increasing tumor size (OR 2.634-11.641, p < 0.05). pT3a disease was associated with a significant increase in positive margins (10.7% vs 5.0%, p < 0.001). Interestingly, pT3a patients with positive margin had worsened survival (5-year OS 75.5% vs 65.9%, p < 0.001). A robotic surgical approach to partial nephrectomy does not increase risk of upstaging to pT3a disease. Those who are upstaged have increased risk of positive margins and associated risk of decreased survival.